The present invention relates to multiple immunochemistry assays on a single element. In particular, the present invention relates to a dry slide containing multiple assays used in a diagnostic analyzer.
Known diagnostic analyzers include clinical chemistry analyzers such as the Vitros® 5,1 FS, sold by Ortho-Clinical Diagnostics, Inc. All such analyzers are collectively called diagnostic analyzers. These diagnostic analyzers can use dry slides, such as those described in U.S. Pat. Nos. 4,258,001, 4,670,381, and 4,997,772, all of which are incorporated by reference in their entireties.
Slides contain an antigen or antibody reactive to the analyte of interest. The various structures of antigen or antibody anchoring in the immune complexes are described in Gosling, Immunoassays, Oxford University Press, 2000, pages 7-15, incorporated herein by reference. A patient sample (e.g., serum or urine) is deposited onto the slide having the label already on the slide. A short incubation follows which enables the analyte being measured to be captured, a portion of the element so deposited with sample is washed to remove uncomplexed labeled immunoreactant and to also add an activator, such as peroxide. A further incubation follows. Thereafter, a portion of the washed portion is read several times with a measurement device as it is incubated further, such as a densitometer or reflectometer to determine the rate of color development, and this rate is compared to calibrated results that are predictive of the concentration of the analyte—e.g., DGXN, PHYT or CRP.
As described above, it is known in the field of immunoassays using dried test elements, that uncomplexed labeled immunoreactants (i.e., antigen or antibody) need to be separated and removed from bound or complexed labeled immunoreactants, prior to detection. This is done by applying, after the sample is added, a wash liquid to the test element after the complexing reaction has occurred, to cause separation of the free labeled immunoreactants from those that are bound. Such separation, in theory, leaves a volume in the test element in which the bound labeled immunoreactants can be read free of the interference of the uncomplexed ones that are now washed away. The process is exemplified by U.S. Pat. Nos. 5,620,860 and 5,641,860, both of which are incorporated by reference in their entireties.
Such immunoassays test elements are typically constructed to test for only a single analyte. Such a construction inherently slows down the throughput of an analyzer by requiring a different test element for each assay desired.
For the foregoing reasons, there is a need for an immunochemistry assay element that is capable of supporting more than one assay.